Pande J, McDermott M J, Callender R H, Spector A
Department of Ophtahalmology, College of Physicians and Surgeons of Columbia University, New York, NY 10032.
Exp Eye Res. 1991 Feb;52(2):193-7. doi: 10.1016/0014-4835(91)90258-g.
The solution structures of the four major components of bovine lens gamma-crystallin, gamma s, gamma II, gamma III and gamma IV are compared using Raman spectroscopy. The spectral region sensitive to the vibrational frequencies of aromatic and sulfur containing residues and to the backbone skeletal stretching modes (500-1000 cm-1), and that reflecting secondary structure (1,000-1,700 cm-1) are strikingly similar in all four gamma-crystallin fractions. These similarities are indicative of the dominant anti-parallel beta sheet structure common to all the gamma-crystallins. A comparison of the ratios of the Raman intensities at 850 cm-1 and 830 cm-1 (I850/I830), an empirical measure of the degree of hydrogen bonding of phenolic hydroxyl groups, suggests that the tyrosine residues in all the gamma-crystallin fractions are moderately hydrogen bonded. Distinct differences in the solution structures of the gamma-crystallins were observed in the higher energy end of the vibrational Raman spectra. The sulfhydryl stretching frequencies for the gamma-crystallins exhibit complex splitting patterns in the 2,500-2,600 cm-1 region. These patterns are due to the competing effects of hydrogen bonding and S-pi interactions with neighboring aromatic residues. All five proteins exhibit multiple, but distinct, thiol frequencies, suggesting that the microenvironments of the cysteine residues in these proteins are significantly different.
利用拉曼光谱比较了牛晶状体γ-晶状体蛋白的四种主要成分γs、γII、γIII和γIV的溶液结构。对含芳香族和硫的残基的振动频率以及主链骨架伸缩模式敏感的光谱区域（500 - 1000厘米-1），以及反映二级结构的光谱区域（1000 - 1700厘米-1）在所有四种γ-晶状体蛋白组分中都极为相似。这些相似性表明所有γ-晶状体蛋白都具有占主导地位的反平行β折叠结构。对850厘米-1和830厘米-1处拉曼强度的比值（I850/I830）进行比较，这是酚羟基氢键程度的一种经验度量，结果表明所有γ-晶状体蛋白组分中的酪氨酸残基都有适度的氢键作用。在振动拉曼光谱的较高能量端观察到γ-晶状体蛋白溶液结构存在明显差异。γ-晶状体蛋白的巯基伸缩频率在2500 - 2600厘米-1区域呈现出复杂的分裂模式。这些模式是由于氢键作用以及与相邻芳香族残基的S-π相互作用的竞争效应所致。所有五种蛋白质都表现出多个但不同的硫醇频率，这表明这些蛋白质中半胱氨酸残基的微环境存在显著差异。
